The 2006 Pima Coun ty Outdoor Lighting Code is the Code in effect regulating the amount of light permitted outdoors within the City of Tucson and Pima County. The Code describes several Lighting Areas that are centered on the various astronomical telescope facilities locate d within Pima County. The Rosemont Mine is within an area of Pima County that is the most restrictive Lighting Area of the Code, namely, Area „E1a . ‟ The maximum amount of light within the Area „E1a‟ is 18,000 lumens per acre from all outdoor lighting sou rces . In addition, a ll outdoor lighting must be full cut off or shielded for Low Pressure Sodium (LPS) , High Pressure Sodium (HPS) , and any other sources. Non - LPS full cutoff is limited to 3,000 lumens per acre, but also contributes to the 18,000 lumens per acre limit. The mine is exempt from complying with the Pima County Outdoor Lighting Code, however, Rosemont Copper plans to operate within the intent of the Pima County Outdoor Lighting Code as long as mine safety and operations are not compromised. To these ends, the mine outdoor lighting design was given special attention, and the results are discussed below. This Revision of the Technical Memo updates the Memo to the impacts of the latest design decisions made by Rosemont Copper.